I have inherited the care of this pool and have not had much luck keeping the pH down. It is approx. 6 year old, 25K plaster pool with an attached spa/hot tub that flows into the pool and sunning deck at 2 points. I have a recently cleaned Jandy SWG and a pentair 520 cartridge filter (and a heater that is only used occasionally). There was trouble with the SWG sensor a month or so ago and the pool balance really got out of whack but we were able to get everything working and in balance. The problem I have is that it takes an awful lot of MA (~32% acid) to keep the pH level in range. The chlorine level is fine, salt concentration %3.4, the filter pressure is 22 psi (It dropped 10psi after I cleaned the cartridges). But this pool seems to eat MA! At least a gal a week. I was warned by the tech that changed my SWG sensor out that I need to stay on top of the chemicals to keep everything harmonious.
We use the water features infrequently (waterfall, bubblers, deck jets), although when filtering, the water flows/falls from the hot tub into the pool.
What am I missing? Or is this just the personality of the pool.
Thanks in advance!